Var
 Vertex:Array[1..2,1..3] of real;
 SideCoef:Array[1..3,1..3] of real;
 La,Lb,Lc,P1x,P2x,P1y,P2y,Xcp,Ycp:real;
 CP_in:Array[1..2,1..3] of real;
 i,j,N:Byte;

Procedure Vert2Ln(x1,y1,x2,y2:real;var C1,C2,C3:real);
begin
 If x1=x2 then
  begin
   C1:=1;
   C2:=0;
   C3:=-x1;
  end
 else
 If y1=y2 then
  begin
   C1:=0;
   C2:=1;
   C3:=-y1;
  end
 else
  begin
   C1:=1/(x2-x1);
   C2:=-1/(y2-y1);
   C3:=y1/(y2-y1)-x1/(x2-x1);
  end;
end;

Function Min(q1,q2:real):real;
begin
 If q1<q2 then Min:=q1 else Min:=q2;
end;

Function Max(q1,q2:real):real;
begin
 If q1>q2 then Max:=q1 else Max:=q2;
end;

Begin
 Writeln('Triangular vertex coordinates:');
 For j:=1 to 3 do
  For i:=1 to 2 do
   begin
    If i=1 then write('x') else write('y');
    write(j,'= ');
    Readln(Vertex[i,j]);
   end;
 Vert2Ln(Vertex[1,1],Vertex[2,1],
         Vertex[1,2],Vertex[2,2],
         SideCoef[1,1],SideCoef[1,2],SideCoef[1,3]);
 Vert2Ln(Vertex[1,2],Vertex[2,2],
         Vertex[1,3],Vertex[2,3],
         SideCoef[2,1],SideCoef[2,2],SideCoef[2,3]);
 Vert2Ln(Vertex[1,3],Vertex[2,3],
         Vertex[1,1],Vertex[2,1],
         SideCoef[3,1],SideCoef[3,2],SideCoef[3,3]);
 Writeln('Line point coordinates:');
 Write('x1= ');
 Readln(P1x);
 Write('y1= ');
 Readln(P1y);
 Write('x2= ');
 Readln(P2x);
 Write('y2= ');
 Readln(P2y);
 Vert2Ln(P1x,P1y,P2x,P2y,La,Lb,Lc);
 N:=0;
 For i:=1 to 3 do
  If SideCoef[i,1]*Lb-La*SideCoef[i,2]<>0 then
   begin
    Xcp:=(SideCoef[i,2]*Lc-SideCoef[i,3]*Lb)/(SideCoef[i,1]*Lb-La*SideCoef[i,2]);
    Ycp:=(SideCoef[i,3]*La-SideCoef[i,1]*Lc)/(SideCoef[i,1]*Lb-La*SideCoef[i,2]);
    if (((i=1) and
        (Xcp<=Max(Vertex[1,1],Vertex[1,2])) and
        (Xcp>=Min(Vertex[1,1],Vertex[1,2])) and
        (Ycp<=Max(Vertex[2,1],Vertex[2,2])) and
        (Ycp>=Min(Vertex[2,1],Vertex[2,2]))) or
        ((i=2) and
        (Xcp<=Max(Vertex[1,2],Vertex[1,3])) and
        (Xcp>=Min(Vertex[1,2],Vertex[1,3])) and
        (Ycp<=Max(Vertex[2,2],Vertex[2,3])) and
        (Ycp>=Min(Vertex[2,2],Vertex[2,3]))) or
        ((i=3) and
        (Xcp<=Max(Vertex[1,3],Vertex[1,1])) and
        (Xcp>=Min(Vertex[1,3],Vertex[1,1])) and
        (Ycp<=Max(Vertex[2,3],Vertex[2,1])) and
        (Ycp>=Min(Vertex[2,3],Vertex[2,1])))) and
        ((Xcp<=Max(P1x,P2x)) and
         (Xcp>=Min(P1x,P2x)) and
         (Ycp<=Max(P1y,P2y)) and
         (Ycp>=Min(P1y,P2y))) then
     begin
      Inc(N);
      CP_in[1,N]:=Xcp;
      CP_in[2,N]:=Ycp;
     end;
   end;
 If ((N=2) and (CP_in[1,1]=CP_in[1,2]) and (CP_in[2,1]=CP_in[2,2])) or
    ((N=3) and (((CP_in[1,1]=CP_in[1,2]) and (CP_in[2,1]=CP_in[2,2])) or
                ((CP_in[1,2]=CP_in[1,3]) and (CP_in[2,2]=CP_in[2,3])) or
                ((CP_in[1,3]=CP_in[1,1]) and (CP_in[2,3]=CP_in[2,1])))) then
  Dec(N);
 Writeln('Number of points = ',N);
 Readln;
End.